129,846 research outputs found
Resolution enhancement of imagestakenby mobile phonecamera
Carey and co-researchers have estimated a super-resolution technique DA SR (Demirel-Anbarjafari Super Resolution), based on interpolation of the high frequency sub-band images obtained by discrete wavelet transform (DWT). Their estimation was carried out by investigating the evolution of wavelet transform extrema among the same type of subbands. Edges identified by an edge detection algorithm in lower frequency subbands were used to prepare a model for estimating edges in higher frequency subbands; and only the coefficients with significant values were estimated as the evolution of the wavelet coefficients. Finally, interpolated high-frequency sub-band images and the interpolated input image are combined by using IDWT to achieve a high resolution output image. The technique has been implemented in Java language in order to be installed on the mobile phones. The DA SR technique has been tested on well-known benchmark images
Locality and measurements within the SR model for an objective interpretation of quantum mechanics
One of the authors has recently propounded an SR (semantic realism) model
which shows, circumventing known no-go theorems, that an objective
(noncontextual, hence local) interpretation of quantum mechanics (QM) is
possible. We consider here compound physical systems and show why the proofs of
nonlocality of QM do not hold within the SR model. We also discuss quantum
measurement theory within this model, note that the objectification problem
disappears since the measurement of any property simply reveals its unknown
value, and show that the projection postulate can be considered as an
approximate law, valid FAPP (for all practical purposes). Finally, we provide
an intuitive justification for some unusual features of the SR model.Comment: 29 pages, minor correction
Computation in Finitary Stochastic and Quantum Processes
We introduce stochastic and quantum finite-state transducers as
computation-theoretic models of classical stochastic and quantum finitary
processes. Formal process languages, representing the distribution over a
process's behaviors, are recognized and generated by suitable specializations.
We characterize and compare deterministic and nondeterministic versions,
summarizing their relative computational power in a hierarchy of finitary
process languages. Quantum finite-state transducers and generators are a first
step toward a computation-theoretic analysis of individual, repeatedly measured
quantum dynamical systems. They are explored via several physical systems,
including an iterated beam splitter, an atom in a magnetic field, and atoms in
an ion trap--a special case of which implements the Deutsch quantum algorithm.
We show that these systems' behaviors, and so their information processing
capacity, depends sensitively on the measurement protocol.Comment: 25 pages, 16 figures, 1 table; http://cse.ucdavis.edu/~cmg; numerous
corrections and update
Languages cool as they expand: Allometric scaling and the decreasing need for new words
We analyze the occurrence frequencies of over 15 million words recorded in millions of books published during the past two centuries in seven different languages. For all languages and chronological subsets of the data we confirm that two scaling regimes characterize the word frequency distributions, with only the more common words obeying the classic Zipf law. Using corpora of unprecedented size, we test the allometric scaling relation between the corpus size and the vocabulary size of growing languages to demonstrate a decreasing marginal need for new words, a feature that is likely related to the underlying correlations between words. We calculate the annual growth fluctuations of word use which has a decreasing trend as the corpus size increases, indicating a slowdown in linguistic evolution following language expansion. This ‘‘cooling pattern’’ forms the basis of a third statistical regularity, which unlike the Zipf and the Heaps law, is dynamical in nature
Extensions of Simple Conceptual Graphs: the Complexity of Rules and Constraints
Simple conceptual graphs are considered as the kernel of most knowledge
representation formalisms built upon Sowa's model. Reasoning in this model can
be expressed by a graph homomorphism called projection, whose semantics is
usually given in terms of positive, conjunctive, existential FOL. We present
here a family of extensions of this model, based on rules and constraints,
keeping graph homomorphism as the basic operation. We focus on the formal
definitions of the different models obtained, including their operational
semantics and relationships with FOL, and we analyze the decidability and
complexity of the associated problems (consistency and deduction). As soon as
rules are involved in reasonings, these problems are not decidable, but we
exhibit a condition under which they fall in the polynomial hierarchy. These
results extend and complete the ones already published by the authors. Moreover
we systematically study the complexity of some particular cases obtained by
restricting the form of constraints and/or rules
Scientific Realism, Adaptationism and the Problem of the Criterion
Scientific Realism (SR) has three crucial aspects: 1) the centrality of the concept of truth, 2) the idea that success is a reliable indicator of truth, and 3) the idea that the Inference to the Best Explanation is a reliable inference rule. It will be outlined how some realists try to overcome the difficulties which arise in justifying such crucial aspects relying on an adaptationist view of evolutionism, and why such attempts are inadequate. Finally, we will briefly sketch some of the main difficulties the realist has to face in defending those crucial aspects, and how such difficulties are deeply related: they derive from the inability of SR to satisfyingly avoid the sceptical challenge of the criterion of truth. Indeed, SR seems not to be able to fill the so-called ‘epistemic gap’ (Sankey 2008). In fact, the epistemic gap cannot be filled in no way other than obtaining a criterion of truth, but such a criterion cannot be obtained if the epistemic gap obtains
Pseudo-Hermitian approach to energy-dependent Klein-Gordon models
The relativistic Klein-Gordon system is studied as an illustration of Quantum
Mechanics using non-Hermitian operators as observables. A version of the model
is considered containing a generic coordinate- and energy-dependent
phenomenological mass-term . We show how similar systems may be
assigned a pair of the linear, energy-independent left- and right-acting
Hamiltonians with quasi-Hermiticity property and, hence, with the standard
probabilistic interpretation.Comment: 2nd Int. Workshop "Pseudo-Hermitian Hamiltonians in Quantum Physics"
(http://gemma.ujf.cas.cz/~znojil/conf
On the Foundations of the Theory of Evolution
Darwinism conceives evolution as a consequence of random variation and
natural selection, hence it is based on a materialistic, i.e. matter-based,
view of science inspired by classical physics. But matter in itself is
considered a very complex notion in modern physics. More specifically, at a
microscopic level, matter and energy are no longer retained within their simple
form, and quantum mechanical models are proposed wherein potential form is
considered in addition to actual form. In this paper we propose an alternative
to standard Neodarwinian evolution theory. We suggest that the starting point
of evolution theory cannot be limited to actual variation whereupon is
selected, but to variation in the potential of entities according to the
context. We therefore develop a formalism, referred to as Context driven
Actualization of Potential (CAP), which handles potentiality and describes the
evolution of entities as an actualization of potential through a reiterated
interaction with the context. As in quantum mechanics, lack of knowledge of the
entity, its context, or the interaction between context and entity leads to
different forms of indeterminism in relation to the state of the entity. This
indeterminism generates a non-Kolmogorovian distribution of probabilities that
is different from the classical distribution of chance described by Darwinian
evolution theory, which stems from a 'actuality focused', i.e. materialistic,
view of nature. We also present a quantum evolution game that highlights the
main differences arising from our new perspective and shows that it is more
fundamental to consider evolution in general, and biological evolution in
specific, as a process of actualization of potential induced by context, for
which its material reduction is only a special case.Comment: 11 pages, no figure
Computation with narrow CTCs
We examine some variants of computation with closed timelike curves (CTCs),
where various restrictions are imposed on the memory of the computer, and the
information carrying capacity and range of the CTC. We give full
characterizations of the classes of languages recognized by polynomial time
probabilistic and quantum computers that can send a single classical bit to
their own past. Such narrow CTCs are demonstrated to add the power of limited
nondeterminism to deterministic computers, and lead to exponential speedup in
constant-space probabilistic and quantum computation. We show that, given a
time machine with constant negative delay, one can implement CTC-based
computations without the need to know about the runtime beforehand.Comment: 16 pages. A few typo was correcte
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